One-Punch Man

ワンパンマン

Saitama, a self-taught hero who trained until every fight ended in a single punch, drifts through City Z bored by his own invincibility. His routine shifts when Genos, a cyborg hunting the rogue machine that destroyed his hometown, witnesses Saitama obliterate a monster mid-battle and demands to become his disciple. Together they register with the Hero Association, where Saitama's unassuming rank belies power that no official test can measure.